Video Cards or Graphics Processing Units (GPUs) differ from Central Processing Units (CPUs) in that they utilize very high speed memory and couple it with a specialized processor that is capable of handling simple calculations on pixel data very efficiently. Video cards are not general purpose processors. However, they can compute, for instance, which surfaces should be visible to a user and which should be hidden as well as what textures should be mapped onto those surfaces to make them look realistic in a three-dimensional (3D) scene much more rapidly than a CPU could accomplish the same task. This is largely due to the fact that while CPUs can adequately perform a variety of general tasks, they are not optimized for any particular operation whereas video cards utilize very specialized hardware to perform only a single function at a time.
Video Cards (GPUs) have traditionally been used for two primary purposes. First, GPUs have been utilized to accelerate simple graphics operations on a user's screen. For instance, when a user scrolls through a document displayed on a display device (e.g., a conventional computer monitor), a large number of pixels are moved around. Due to the computational demand such action places, traditional CPUs are not exceptionally rapid or efficient at accomplishing this task. As such, a GPU may be utilized in conjunction with the CPU to achieve more rapid and efficient scrolling.
Secondly, GPUs have been utilized to render simple primitives (e.g., to fill an area with a color, draw a line, or the like). As with acceleration of simple graphics operations, GPUs can more rapidly and efficiently render such simple primitives than traditional CPUs.
More recently, video games have started to become more popular causing the demand for increased realism and speed in such games to increase. As such, video game manufacturers have begun to tackle complex issues of video rendering, for example, rendering a three-dimensional scene while providing shading, reflections, texture mapping, and the like to make the scene look as realistic as possible while still rapidly responding to user input.
Outside of the particular areas mentioned above, video cards have not been utilized to accelerate CPU functions.
Use of digital images in arenas outside of video game manufacture has also enjoyed a recent increase. However, as digital images get bigger (more megapixels) and pixels get deeper (at least 16 bits per channel), they are straining the computational resources available in traditional CPUs resulting in slower, less efficient digital image processing.